Phototherapy is exposure of a subject to either natural sunlight or light generated by an artificial light source in order to treat a lesion, disease, or condition of the subject. Certain wavelengths or a range of wavelengths of light have been found to provide optimal therapy for particular lesions, diseases or conditions. The UVB range is an example of a particularly therapeutic range of wavelengths.
Light emitting diodes are a light source that may be used to generate light in a wavelength range suitable for use with phototherapy. A light emitting diode comprises a two-lead semiconductor light source, which emits light when activated. When a suitable voltage is applied to the leads of a light emitting diode, energy is released in the form of photons. Modern light emitting diodes may be configured to release photons of various wavelengths including wavelengths in the ultraviolet range including wavelengths in the UVB range.
Phototherapy is currently used to treat a range of disorders and diseases including dermatologic diseases, sleeping disorders, and psychiatric disorders.